The present invention relates to contrast media for radiography, and more particularly to the preparation and use of iodinated organic carbonates as contrast media for radiography. More specifically, the present invention relates to the preparation and use as radiographic media of iodinated benzyl carbonates, p-iodo-sec-phenethyl carbonates (sec means secondary or two groups attached to the same carbon atom of the ethyl moiety), p-iodo-phenethyl carbonates, p-iodo-phenyl carbonates, 3-(p-iodophenyl)propyl carbonates, 3-(p-iodophenyl)butyl carbonates, 2-(p-iodobenzyl)butyl carbonates and 2-(p-iodobenzyl)-n-hexyl carbonates.
Myelography and possibly other X-ray applications for body cavities have been performed with iodinated oils. Such radiographic agents after being introduced into the subarachnoid space or other body cavities must be withdrawn because of their incomplete absorption even after periods of several years. Other areas of radiography, lymphography and bronchography utilize contrast media which have proven to be irritating and slowly eliminated, and to produce undesirable side effects in addition to being difficult to administer.
Illustrative prior art methods and compositions for radiography are disclosed in U.S. Pat. No. 3,178,473 issued Apr. 13, 1965 to H. Haltermann et al. for "Process for the N-alkylation of Acyl Anilides Halogen Substituted in the Nucleus"; U.S. Pat. No. 2,386,640 issued Oct. 9, 1945 to W. H. Strain et al. for "Bis Esters of Iodinated Phenyl Aliphatic Carboxylic Acids"; U.S. Pat. No. 3,235,461 issued Feb. 15, 1966 to E. Habicht et al. for "Esters of 3,5-Diiodo-4-Pyridone-N-Acetic Acid"; and U.S. Pat. No. 2,348,231 issued May 9, 1944 to W. H. Strain et al. for "Compounds for Use in Radiography."